The present invention relates to apparatus by which flameout conditions in ionization detectors are monitored within an environment of widely varying temperature. Flame ionization detectors are commonly used in analytical equipment, such as gas chromatographs, wherein the environmental temperature varies widely and the flame status of each ionization detector must be monitored to assure that the results derived therefrom are accurate. Hitherto, the most common approach taken to the monitoring of flame status in such equipment had been to hold a polished metal object above the flame exhaust and observe whether a fogging condition occurs thereon. Of course, this approach is predicated on the theory that such fogging will only be caused by water vapor in the exhaust when the flame is lighted. Therefore, flame status very often becomes more difficult to detect with this approach when the environmental temperature within the equipment is between room temperature and the temperature of the exhaust.